Double jib gantry crane



United States Patent [72] Inventor Guy 11. Strayer Manchester Beach R.D., 2, Fairview, Pa. 16415 [21 1 Appl. No. 682,756 [22] Filed Nov. 14, 1967 [45] Patented Dec. 15, 1970 [54] DOUBLE JIB GANTRY CRANE 3 Clalms, 3 Drawing Figs.

[52] U.S. Cl. 212/10, 212/63, 212/65, 212/28, 212/38 [51 lnt. Cl ..B66c 17/00, B66c 23/02, B66c 23/00 [50] Field of Search 212/10- [56] References Cited UNITED STATES PATENTS 2,912,121 11/1959 Moyer 212/17 FOREIGN PATENTS 338,754 7/1921 Germany 2l2/1Q 289,879 10/1931 Italy 212/17 Primary Examiner-Harvey C. Hornsby Attorney-Charles L. Lovercheck ABSTRACT: The crane disclosed herein is a double jib gantry crane having a jib at each side. The crane is carried on four spaced supporting wheels. Each jib is supported on a rotatable column through 320. Each said column is supported between two wheels on a single side and spaced inward a substantial distance from the adjacent wheel so that a load on the jibs will not upset the crane but will be imposed as a movement about the axle of the adjacent wheel. A floating trolley is supported on top of the crane to give travel in four directions without moving the crane. The gantry crane wheels are driven by means of chains and sprockets.

PATENTEU BEE] 5 WI SHEET 2 OF 2 INVENTOR. Y TRAYER DOUBLE .IIB GANTRY CRANE Cranes are frequently supported in a building on the building structure itself. This requires the building to be made of heavy construction and the framework of the building strong enough to support the maximum load to be carried by the crane. Applicant has provided a crane that can be used in a building and supported on the floor of the building so that the framework of the building needs to beonly strong enough to support the building itself and does not have to'be strong enough to support the crane inadditionto'the building.

The crane disclosed has a jib extending from each side thereof and the jib is supported on the column that is spaced rearward from the wheel adjacent to which it is attached. A floating trolley is supported on the top of the crane.

It is, accordingly, an object of the invention to provide an improved crane.

Another object of the invention is to provide an improved gantry crane having a jib on each side. I

Another object-of the invention is to provide an improved floating trolley in combination with a jib crane;

With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawing and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions, and minor details of construction' without departing from the spirit or sacrificing any of the advantages of the invention. I

In the drawings: 4

FIG. 1 is a frontview of the crane according to the invention shown inside a building;

FIG. 2 is a side view ofthe crane shown in FIG. 1;

FIG. 3 is a top view of the crane according to the invention.

Now with more particular reference to the drawings, the

gantry crane shown is indicated generally at and has a jib 11 supported on one side and a jib 12 supported at the other. The gantry has end frames 13 and 14 that-are connected by the top frame 15. A floating trolley 16 is supported on the top frame on the lateral tracks 31 and 32 which extend from one side of the crane to the other. The wheels 33 on the trolley rest on the tracks 31 and 32.

The trolley 16 has an upper frame 51 to which the wheels 33 are attached. The wheels rotate around the'axle 52 and the trolley may be driven laterally by means of a motor indicated at M, which may be connected to wheels-33 or the motor could be deleted and the trolley be freer floating. Downwardly extending links 54 support the track 50 and wheels 55 on hoist 23 move laterally over the track 50 from side-to side. The hoist 23 is an electrical hoist and with it, the hook 56 can be raised or lowered to lift a suitable load. The 'hoist 23 can travel the entire distance from side to side of tracks 50; I

The jibs 11 and 12 are each supported on a column 28. The

columns 28 are pivotally supported in bearings 36 and in bearings 37 at the top. The jibs each have a horizontal boom 27 fixed to the column 28 and a line 38 is fixed to the outer end 39 of the boom and to a supportdll on the column. A suitable hoist 24 is supported on each jib so that a load can be lifted by the jib. i

A motor 26 is operably connected to the column 28 in a suitable manner so that the column 28 can be rotated through 320. Thus a load can be lifted at any position under the gantry or behind or at the side or in front of the gantry. A suitable nected to wheels- 17 andthey extend upwardly to the cross shaft 41 so that the motor 22 will drive two of the wheels 17 at a unifonn rate. The hoist 23 is supported on t'rack 50 of the floating trolley 16 and suitable actuating. motor will be provided to lift and lower the hook The drive could be hydraulic instead of electric.

The entire crane may be supported in a building 29 which may be of relatively light construction and have a suitable floor supported on the ground 43. Tracks 18 for the ground engaging wheels 17 will likewise besupported on the ground It will be noted that the crane itself can be supported on a suitable rubber tire if it is desired not to use tracks.

It will be noted that the side frames are provided with laterally spaced vertically extending members that are connected by the bridge members 19. A base 'member 45 is attached to wheels 17 at each of its opposite-ends and it will be noted that the bearing 36 that supports column 28 is on the side of one of wheels 17 between that wheel and spaced from that wheel 17 a substantial distance so that crane 10 will not overturn when a load is placed on hoist 24, when it is disposed at the outer end of the horizontal boom 27. Rather, the weight of the crane acting around the axle of the wheel 17 that is outboard of the bearing 36 will counterbalance the weight on the hoist 24. Thus the jibs 12 will have a moment arm around the axle of the wheel 17 that is closest to the .bearing 36 and there will be a little tendency for the crane to be tipped over when a rated load is lifted on the crane.

The foregoing specification sets forth the invention in its preferred practical forms but the structure shown is capable of modification within a range of equivalents without departing fromthe invention which is to be understood is broadly novel as is commensurate with the appended claims.

lclaim: v

1. A crane comprising spaced end frame members, each said end frame member having spaced supporting wheels,

a top frame attached to said end frame members and extending therebetween,

drive means on said crane for driving said wheels,

a column on each said end frame, 7

each said column being pivotally supported at its lower end on a said end frame,

a boom fixed to each said column and extending outwardly therefrom,

and means to rotate each said column to swing the said boom attached thereto in a horizontal plane through an angle of approximately 320,

a floating trolley is supported on said top frame,

said top frame. having spaced tracks extending generally from one said end frame member to the other,

and means to drive said trolley along said end frame tracks,

and said trolley having a track thereon generally perpendicular to said first mentioned tracks and a wheeled hoist having its wheels resting on said trolley tracks,

means to move said trolley from one side of said gantry to the other,

and cable means on said hoist extending downwardly therefrom.

2. The crane recited in claim 1 wherein said columns are each supported between said supporting wheels on one side of said gantry.

3. The crane recited in claim 2 wherein said crane is supported in a building, said building being only slightly higher than said'gantry and slightly wider than said jibs and gantry crane. 

